It's recommended that you don't wear artificial nails for more than a few weeks at a time - say a month maximum. Then remove them and give your natural nails a chance to breathe and refresh their growth.
It's also important that you always use proper nail adhesive and never just ordinary glue you might find around the house.
To remove artificial nails, soak them in a non-acetone polish remover until they start to dissolve and come away. It’s very important to avoid acetone and other chemicals with an acetone-base. They will damage the surface of the nail, affecting the shine and also thin and weaken the nail plate.
Also, don't try to peel off the artificial nails without first soaking them in polish remover, and certainly never, ever try to break them. This could result in serious damage to your own nails below.